Header construction and heat transfer apparatus



H. M. HOPE F eb. 20, 1934.

HEADER CONSTRUCTION AND HEAT TRANSFER APPARATUS Filed Nov. 30, 1931 2 Sheets-Sheet 1 INVENTOR. Harry M Hope BY ,Jc

A TTORNE Y.

Feb. 20, 1934. H. M. HOPE 1,943,330

HEADER CONSTRUCTION AND HEAT TRANSFER APPARATUS Filed Nov. so. 1931 2 Sheets-.Sheet 2 BY Jloutp lu uli,

ATTORNEY.

' Parented Feb. 20, 1934 UNITED STATES HEADER CONSTRUCTION AND 'HEAT TRANSFER APPARATUS Harry M. Hope, New York, N. Y., assignor to Alco Products, Incorporated, a corporation of 1 Delaware Application November 30, 1931 Serial No. 577,872

6 Claims.

My invention relates to a header construction and heat transfer apparatus.

In designing tube stills and heat transfer apparatus having header construction, it has been appreciated that a closer spacing of the tube centers will result in a higher velocity of the gases permitting an increased rate of heat transfer. With a' higher rate of heat transfer, a

smaller minimum surface is required permitting a greater fiexilibity in design. Hitherto, the general practice has been in the case of four inch tubes for example, to place them on six and three quarters to seven and one half inch centers.

One object of my invention is to provide a header construction which will permit placing of the tubes much closer together than has hitherto been able to be accomplished.

- Another object of my invention is to provide I a heat transfer apparatus employing the header of my invention.

Other objects will appear from the following description:

Figure 1 shows a plan of the tube assembly in a heat transfer apparatus embodying my instruction embodying my invention.

, Figure 4 is a sectional view taken on the line 44;of Figure 3, showing a section of a'header embodying my invention.

Figure 5 is a plan view of a header embodying my invention.

Figure 6 shows a section of a modification of a header construction embodying my invention.

In general, my invention contemplates a header construction having the form of a J-bend, that is a U-bend having one arm longer than the other. This U-bend having one short arm, will be hereinafter referred to as a J-bend. The ends of the J-bend are provided with seats against which is seated tube receiving means.

More particularly referring now-to. the drawings: Figure 4 shows a section of a header embodying my invention in which the J-bend is designated by reference character 1. It is to be understood that like reference characters are herein used to indicate like parts throughout the drawings. 2 indicates the seats provided at the ends of the J-bend. These seats may be of any suitable type and inasmuch as my invention is particularly adaptable for use with high pressure oil stills, I have shown a metal to metal joint. For other constructions, if desired, appropriate gaskets may be used. The ferrules 3 are provided with internal means 4, into which the tubes are rolled to form a pressure tight joint. The ferrule 3 is provided with a pair of integral extensions 6 and '7. The upper ends of the extensions 6 and 7 are provided with open-- ings 8 through which a member 9 is positioned. The member carries a set screw 10 which is adapted to screw down and exert a thrust against seats 11 which are integral with my J- bend, as is obvious from the drawings. When screw 10 is screwed downwardly, a thrust is exerted against seat 11 and transmitted through the strong back to the bifurcated extensions 6 and 7 of the ferrule 3, thus forcing the ferrule against the seat on my J-bend. It is to be noted that the seats 11 are conical in o der that the thrust-may be equalized between the pair of extensions 6 and 7.

It is to be remembered that, while I have shown one method of exerting thrust to effect a tight joint between the ferrule and the J-bend seat, that any suitable means may be used without departing from the spirit of my invention. In the form shown in Figure 6, ferrules 3 are made integral being joined by a web 12. The extensions and other construction are the same as in the form shown in Figure 4.

In use, referring now to Figures 1 and 2, tubes 4 are placed through tube sheets 14 and the ends of the tubes are rolled into ferrules 3,

care being taken that the integral extensions 6 and 7 are in the same longitudinal plane. 00 After two adjoiningtubes have been fitted with ferrules 3, the J-bend is placed in position,'the strong back is put in place and the set screw 10 is advanced to its seat to exert a pressure which will seat the J-bend and ferrules together. 9 It is to be understood that ferrules having long extensions will alternate with ferrules having short extensions in order to accommodate the J-bend. In order to save time in the installation and to preclude any chance of error, the type of double ferrule shown in Figure 6 may be used. The ferrules at opposite endsof 'the same tube will have long and short extensions. In other words, if a ferrule having a long extension is used at one end of an individual tube, its other end must have a ferrule having a short extension. The tubes 4 are of equal length and their ends will be staggered, due to the effect of the J-bend.- special fittings 13 having a 90 bend and terminating with a flange at one end and a seat at the other, are used for inlet and outlet fittings.

It will be readily appreciated that with my construction a compact bank of tubes can be expeditiously and quickly assembled. The construction is very simple and, while I have intended my construction for use in closely spaced tubes, it is obvious that my invention can be applied to a tube bank having any given interspatial dimensions.

Thus it will be seen that I have accomplished the objects of my invention. I am enabled by the construction of my invention to construct a heat interchanger in which the tubular heat exchange surface is formed of closely spaced tubes. Thus, for example, if the diameter of the tubes be four inches, I am enabled to space the tubes with an interaxial dimension of five inches which will give a clearance of only one inch between adjacent tubes in the same level. This it will be seen gives a clearance of one half the radius of the tubes. This result has never before been accomplished and it is manifest that a high velocity of the heating medium will take place in its flow through the tube bank. This increased velocity of flow will give a higher rate of heat exchange and will enable me to construct a heat interchanger which will give the minimum surface required with a smaller design. Due to my J -bend construction, the ferrules may be of uniform size and sufliciently thick to permit a joint having a high factor of safety.

It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of my claims. It is further obvious that various changes may be made in details, within the scope of my claims, without departing from the spirit of my invention. It is, therefore, to be understood that my invention is not to be limited to the specific details shown and described.

Having thus described my invention, what I claim is:

1. In a heat transfer apparatus, the combination including a plurality of tubes of equal length, a tube sheet, the ends of alternate tubes projecting a given distance from said tube sheet, the ends of complementary alternate tubes being spaced a greater distance from said tube sheet, and J-bends joining adjacent tubes.

2. In a heat transfer apparatus, the combination comprising, a plurality of tubes of equal length, a tube sheet, said tubes being disposed in said tube sheet with alternate tubes projecting a greater distance from said tube sheet than the complementary alternate tubes, ferrules having bifurcated extensions, said tubes being secured in said ferrules, pressure-exerting means carried by said extensions, J-bends seated on said ferrules and means on said J-bends for receiving thrust whereby to form tight joints between said J-bends and said ferrules.

3. A removable header for heat exchange apparatus comprising in combination a J-bend, seats on the J -bend, ferrules adapted to be seated on said seats and means for securing said ferrules in seated position.

4. A removable header of the character described comprising a J-bend provided with seats, ferrules adapted to be seated on said. seats, extensions on said ferrules, means on said extensions for receiving bridge members, pressure-exerting means mounted on said bridge members, bearings on said J-bend for receiving the thrust exerted by said pressure-exerting means whereby said ferrules are pressed against the said seats.

5. The combination with a header having a J-bend provided with seats of a tube receiving member having an integral pair of ferrules, each provided with a bifurcated extension adapted to transmit a ferrule-seating pressure to said ferrules to hold them on the J-bend seat.

6. In a heat transfer apparatus, a tube, a removable J-bend header secured to each end thereof, the long leg of one of said J-bends being secured to one end of the tube and the short leg of the other J-bend being secured to the other end of said tube.

HARRY M. HOPE. 

